During conversion of `docs/FAQ` into Markdown, 'man ld' has incorrectly
kept one of its quotes when it was surrounded by backticks for inline
code formatting. A space on the left of it was lost as well.
Fix the formatting in the new `docs/FAQ.md`.
Closes#20812
- drop stray duplicate empty lines in docs, scripts, test data, include,
examples, tests.
- drop duplicate PP parenthesis.
- curl-functions.m4: move literals to the right side in if expressions,
to match rest of the source code.
- FAQ.md: delete language designator from an URL.
- packages: apply clang-format (OS400, VMS).
- scripts/schemetable.c: apply clang-format.
- data320: delete duplicate empty line that doesn't change the outcome.
- spacecheck: extend to check for duplicate empty lines
(with exceptions.)
- fix whitespace nits
Closes#19936
